A young infant with projectile vomiting in hypertrophic pyloric stenosis.
In contrast to newborns and infants with gastroesophageal reflux with possetting or
vomiting in a short curve since birth, the vomiting in hypertrophic pyloric stenosis starts usually on the transition from the neonatal period to the beginning of the second month of life, and there is a gradual increase in frequency of vomiting to a so-called projectile vomiting. Projectile vomiting occurs during or shortly after feeding, is a very forceful ejection which travels in a flat arc shape for several feet as shown in the drawing , and there is a large amount of milk, formula or tea.